Sacral fatigue fractures are often seen in athletes and elderly patients with osteoporosis, and we have experienced a case of man in his 50s in whom we initially suspected metastatic sacral tumor. The patient was 173 cm tall, weighed 100 kg, started working as garbage collector. He had pain in the coccyx around. The pain spread from his right hip to the posterior of his lower extremity, making it difficult for him to walk. He was referred to our pain clinic due to severe pain. A lumbar spine MRI T1-weighted sacral coronal sectional image was taken, and a metastatic sacral tumor was suspected. A CT scan taken revealed a sacral fatigue fracture. The patient's pain gradually decreased, and the oxycodone dose was reduced and discontinued, and the patient was finally diagnosed. The diagnosis of sacral fatigue fracture requires a thorough history of the patient's life, and MRI imaging is essential to obtain adequate views of the sacral region.

Osteoid osteoma accounts for 10％ of primary benign bone tumors and is rarely encountered in pain clinics. It frequently affects young people. A 17-year-old female patient experiencing nocturnal arousal due to left elbow pain presented to the pain clinic. She reported a gradual increase in pain for 6 months. At the time of presentation, she had rest pain of 9/10 on the numeric rating scale (NRS), heat and swelling of the elbow joint, and mild difficulty with elbow extension. The pain decreased to NRS 3/10 after administration of loxoprofen but flared within approximately 6 h. Computed tomography showed osteoid osteoma of the humerus within the elbow joint. The osteoid osteoma was arthroscopically removed, and the pain resolved after surgery. Night pain is a typical symptom of osteoid osteoma and responds well to nonsteroidal anti-inflammatory drugs. Although osteoid osteoma is rare, it is an important differential diagnosis for pain in adolescents.